I have had many instances of this crash now. I animate:


- inside the Matnet, an "old" VEX Material builder, I animate the Environment Map rotation ("ogl_envrotate")
- current production build 20.5.445
- OpenGL viewport

So, this is not only "sensitive" to simulations with GPU.

Hello, please I have fast camera movement (and particles) and I am using the Motion Blur LOP. I attached a simplified node graph.

If I use only the File Cache node, the Motion Blur is corrupted in the render. If I disable the filecache and let Karma get its samples directly from the SOP Import LOP, the Motion Blur is fine.

Is it technically correct to use the Cache LOP node and reference the camera shutter times manually (because the Camera Primitive is not present when caching the particles?)

It is also unfortunate, that these settings snap the Time Bar (the Playhead) to the frames in steps (1,3,5,...)

- Integer Frame Values: ON
- Step: 2

What would seem logical to me would be this:

- Project FPS set to 50
- Integer Frame Values: ON
- Step: 2
- Viewport playing in realtime would report green 25, as in this image

My SOP animations usually evaluate realtime at 25 FPS, but I have to render 50 FPS.

There is an option in the "Global Animation Options" to STEP the playback, but I am not sure if that works as expected.

I have tried these:

Integer Frame Values: ON STEP: 10
(extreme step value to test)
Houdini still tries to playback 50 FPS. There is no skipping in the viewport.
CPU load is the same as without stepping.

Integer Frame Values: OFF STEP: 10
Houdini skips frames.
Viewport reports low FPS (the FPS number in viewport should be green if Houdini manages to playback in realtime)


Please, do you use these? What is your experience and best practices, please?

Sean, thank you so much for the info about the "Edit data channels". I love CHOPs. I lived under the impression, that I could animate the constant (or a channel). I believe I could animate an attribute in SOPs and import the value into a channel. The "Edit data channels" is super useful. Thank you!

(I have sent the crash log and .hiplc file to Side FX so that they could try to reproduce it again)

Btw I have:
- Nvidia drivers 560.81
- RTX 4090
- Two monitors

I don't know what else might be related to the issue.

You were right, after few flawless weeks, I have the same issue, again.

This time I was working on a Vellum simulation, animating some forces (inside the dopnet), interrupting the simulation, tweaking the keyframes... running the sim again ... and then duplicated keyframes occurred and Houdini crashed after few more clicks.

I am on 20.5.370 currently (since it was released), nothing else have changed on my PC.

I had two instances of Houdini running at the same time, when the issue occurred (one Houdini was idle, with just a simple setup, no simulation).

I would really like to help. I was really thinking, what may have I done to fix it. But I believe that I only uninstalled and reinstalled Houdini. Now I don't have those issues. I moved my pref dir out of synced documents (OneDrive), but that alone did not help I believe.

I had a Perforce package installed for a little while (which was introduced few days later, as a part of Houdini). But that is probably not related too.

Hi Rifs. On my computer, everything got fixed when I uninstalled Houdini and reinstalled it again. I have no such problems anymore.

eikonoklastes, thank you very much. I will try that!

I have also tried to uninstall Houdini 20.5 and install it again. Some of the test scenes that I had seem to work fine so far (even with the "faulty" hchanneleditor.pref). So, I hope, that it was only a glitch.

In the past, I had a crash during an update to a daily build. The update crashed (probably) because I had a Houdini instance running in another desktop and I did not notice it (I have already filed a RFE, that the Launcher should check that). Launcher reported, that the Repair of the update was successful, but ... maybe it wasn't.

I will send more information to the SideFX support.

Thank you very much again!

Since the 20.5 I have quite frequent crashes (like ~10 daily) when working with Animation Editor. I am trying to reproduce it, and SideFX Support also tried it with many of my inaccurate descriptions. Unfortunately I don't know what is the main reason for A.E. to become "broken" so I would like anybody to give me some hint, what to try.

A.E. "gets broken" after few minutes or hours of work. Then it behaves this way:

- I don't see the Time Bar (although it is turned on)
- I don't see the rectangular selection marquee (when selecting keyframes)
- I am not able to pan the channels in A.E.
- the keyframes get multiplied

Multiplication of keyframes looks like this:
- I move a keyframe (let's say from time 10 to time 50)
- I play the animation
- I press Ctrl+Z
- the keyframe goes back to the time 10, but the keyframe at time 50 remains in the channel, so now I have both of them

This is usually followed by a Houdini crash after few more clicks.


It probably helps to delete "hchanneleditor.pref" before the next session, but I don't have any other clue what could be the main cause. It seems to happen more often when I animate sources for a GPU simulation ... then, houdini is not responsive "often" (which is normal) ... and A.E. gets corrupted more often.

I have Windows 11, current Houdini daily build (usually) and I have the newest nvidia studio drivers.

@mchaput Thank you very much again! I have the current build and the sorting and working with attributes is great!

I have also seen, that you are the author of the Houdini icons and lots of Houdini UX and UI. I really admire all of that! <3

ajz3d
I tend to avoid network boxes because of this problem with automatic layout

I have exactly the same problem for many years, since they have been introduced. I have been quiet for too long :]

I am thinking about making my own Python wrapper around the layoutChildren() function.

- store all network boxes in a list
- delete all network boxes
- layoutChildren()
- recreate the network boxes

It is not that complicated to do, and quite tempting to have them layout fine.

Thank you very much! The "Layout Nodes Up" is quite good, as long as it does not layout two separate streams (preview attached).

@pezetko did you submit it as a bug? The #140575 is confirmed ID of the bug?

Please, look at the attached picture. The command "Lay Out All" or "Lay Out Selected" doesn't work nice here. Can I do something to make the automatic layout look similar to the third layout?

I am just curious:

- yesterday I updated to 20.5.332 and I believe it was a daily build
- today I noticed, that there is a new production build, 20.5.332 (same number)
- I started a Houdini Launcher and it automatically offered an update to 20.5.332

Is it common, that a certain daily build is "promoted" or "approved" to the production build? Are there no differences in those builds?

I have submitted it as a RFE ID# 140362 ... if anyone wants to add or specify, I will be glad.

Hi, thank you! I have reported this as it should have been reported:
https://www.sidefx.com/bugs/submit/ [www.sidefx.com]

Btw these days I got a lot of fixes from support and developers. Some of them were fixed within hours after they reproduced the issue. Including the hotkeys. And they were ready for download in the next day build. So I would like to thank support and developers and encourage you to RFE with this bug/submit URL too. Best Regards.

This command returns time when the definition was last modified:


or just raw, to compare it with the unlocked definition:

Is it a good RFE to add the information (from my previous post) into the Node Info? Or am I missing some workflow?